The most common type of insect sting allergy is caused by honey bees followed by vespids which include hornets, yellowjackets and wasps. The venom allergens of honey bees are proteins of known structures and those of vespids are of unknown structures. One aspect of the proposed work is to elucidate the primary structures of two families of homologous venom allergens of vespids, antigen 5s and phospholipases A1. Their primary structures will be determined by cDNA and protein sequencings. Having the structures of a family of homologous proteins can facilitate the structure-function analysis of a molecule. The structural data will help to clarify the common clinical observation of multiple sensitivity of vespid allergic patients which can be due to multiple exposure and/or cross reactivity of vespid venoms. Another aspect of the proposed work is to delineate the T and B cell-specific antigenic sites of bee and vespid venom proteins. Various fragments of venom proteins will be tested for their affinity of venom-specific antibodies and for their capacity to stimulate or suppress venom-specific antibody responses in mice. The venom fragments will be prepared by chemical degradation of venom proteins and/or by peptide synthesis. Alternatively they may be prepared biosynthetically after appropriate modification of venom-encoding cDNAs. The findings may lead to the design and development of vaccines for treatment of insect allergy. The findings can also contribute to our knowledge whether or not the same epitopes of a protein are involved in the recognition by different B cells and helper or suppressor T cells.